The striped bitterling (Acheilognathus cyanostigma), a species of the family Cyprinidae, is naturally
distributed in the Kinki region of central Japan. This species is spreading to various other areas due to the
release of juvenile ayu (Plecoglossus altivelis) from Lake Biwa. This species has been reported in the
Monobe, Kagami, and Niyodo river systems in central Kochi Prefecture, where it has been considered as an
artificially introduced species. However, there is no documented record based on voucher specimens. We
conducted meristic and morphometric analyses on bitterling specimens deposited at the Lake Biwa Museum
and confirmed that three specimens collected from the Monobe and Watari rivers in Kochi Prefecture were
A. cyanostigma.
